Poly saccharides

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Poly saccharides. Poly saccharides. Polysaccharides are polymers of D-glucose Important polysaccharides are: Starch ( Amylose and Amylopectin ) Glycogen Cellulose Chitin. D-Glucose. - PowerPoint PPT Presentation


<p>Carbohydrates</p> <p>Polysaccharides1Polysaccharides are polymers of D-glucose Important polysaccharides are:Starch (Amylose and Amylopectin)GlycogenCelluloseChitin</p> <p>D-GlucosePolysaccharidesInsoluble store of glucose in plantsformed from two glucose polymers: (Amylose, Amylopectin)</p> <p>StarchStarch (Amylose, Amylopectin)Amylose is a continuous chain of glucose molecules linked by -1,4 glycosidic bonds.Amylopectin is a branched chain of glucose molecules linked by -1,4- and -1,6-glycosidic bonds.Amylose</p> <p>-glucose1,4 glycosidic bondsSpiral structureAmylopectin</p> <p>-glucose1,4 and some 1,6 glycosidic bondsBranched structure</p> <p>StarchStructures of Amylose and Amylopectin </p> <p>GlycogenGlycogen is similar to amylopectin, but more highly branched.Insoluble compact store of glucose in animals-glucose units1,4 and 1,6 glycosidic bondsBranched structure</p> <p>GLYCOGENIt is the main reserve food in animals and is often called animal starch.Glycogen is stored in the liver and muscles of animals Structure:Glucose polymer, similar to amylopectin,but even more highly branched more (16) branches. - (1 -&gt; 4) linkage and - (1 -&gt; 6) linkag 1 : 12Uses: The highly branched structure permits rapid glucose release from glycogen stores, e.g., in muscle during exercise. The many branched ends provide a quick means of putting glucose into the blood. The ability to rapidly mobilize glucose is more essential to animals than to plants. Animals store glycogen in the liver (about a one-day supply in humans) and use it to maintain fairly constant blood sugar levels between meals8StarchesGlycogen</p> <p>more branchingStarch/Glycogen</p> <p>CelluloseStructural polysaccharide in plants-glucose with -1,4 glycosidic bonds</p> <p>Cellulose</p> <p>Cellulose</p> <p>CelluloseCellulose is the major structural polysaccharide of plants. It is a long thread like molecule. Cellulose is the main constituent of cell walls of plants. The role of cellulose is to impart strength and rigidity to plant cell walls, which can withstand high hydrostatic pressure gradients. Cellulose is a polymer of glucose molecules linked by -1,4 glycosidic bonds.Enzymes in saliva (e.g. salivary amylase) can hydrolyze -1,4 glycosidic bonds in starch, but not -1,4 glycosidic bonds in cellulose.</p> <p>CelluloseMost organisms cannot digest (hydrolyze) cellulose Organisms that can digest cellulose include the microorganisms living the gastrointestinal tract of many organisms typified especially by cows and termites and many fungi (i.e., the things that eat the wood of fallen trees)ChitinChitin is another example of a structural carbohydrate.Chitin is found in the exoskeletons of insects and spiders.Chitin is also found in the cell walls of fungi.Chitin is leathery in pure form but is hardened in most uses via the deposition of calcium carbonate.Chitin</p> <p>Chitin</p> <p>Some Familiar and Important Complex Carbohydrates</p> <p>(a)The Polymer Amylose is a Major Component of Starch and is made Up of Alpha-D-Glucose Monomers.</p> <p>(b)The Polymer Cellulose, which Consists of Beta-D-Glucose MonomersPolysaccharidesGlucose is the monosaccharides of the following polysaccharides with different linkages and branches a(1,4), starch (more branch)a(1,4), glycogen (less branch) a(1,6), dextran (chromatography resins)b(1,4), cellulose (cell walls of all plants)b(1,4), Chitin similar to cellulose, but C2-OH is replaced by NHCOCH3 (found in exoskeletons of crustaceans, insects, spiders)</p> <p>21AmylosePolymer with -1,4 bonds</p> <p> -1,4 bonds</p> <p>AmylopectinPolymer with -1,4 and -1,6 bonds branches -1,6 bond</p> <p> -1,4 bonds</p> <p>CellulosePolymer with -1,4 bonds</p> <p> -1,4 bonds</p>